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51.
Plant-parasitic nematodes pose a major threat to crop production in Nigeria. Comprehensive data on yield losses for most cereal crops are not readily available. Research on maize (Zea mays), rice (Oryza sativa), and sorghum (Sorghum bicolor) has shown an 18%–67% reduction in yield linked to the destructiveness of parasitic nematodes, particularly root-knot and root-lesion nematodes. Continuous monoculture and a conservative approach to agriculture increase the incidence and population density of nematodes, leading to higher levels of damage and losses in most cultivated cereal crops. These losses affect the food security of the growing population of Nigeria and many African countries that are heavily dependent on cereals. The accurate identification of nematodes is fundamental for effective management strategies. Nematode taxonomy based on morphology has been difficult due to intraspecific character variations coupled with the limited expertise of indigenous nematologists. Biochemical and molecular marker-based tools and approaches have allowed efficient diagnosis of most nematode species affecting cereal production globally. These approaches have proved useful due to their practicality, rapidness, accuracy, and cost-effectiveness. This review describes the important economic effects of these parasitic nematodes on cereal production and highlights the need for integrative approaches to taxonomy for accurate species identification that will improve nematode diagnosis, thereby contributing to the increase of food production in Nigeria.  相似文献   
52.
【目的】研究旨在分析场、出生季节、出生月份、出生类型和性别对湖羊初生重性状的影响,并估计该性状的遗传力。【方法】运用SAS 9.2软件对2021年新疆地区3个规模化湖羊养殖企业共计4 570只母羊所产的8 352只羔羊初生重作非遗传因素分析,使用DMU软件对湖羊初生重性状进行方差组分估计,并使用两种单性状动物模型估计该性状的遗传力,根据赤池信息准则(Akaike’s information criterion, AIC)确定最佳固定效应组合和动物模型。【结果】场、出生季节、出生月份、出生类型和性别对湖羊的初生重均有极显著影响(P<0.01)。场1和场2羔羊初生重无显著差异(P>0.05),且均极显著大于场3羔羊的初生重(P<0.01);冬季出生的羔羊的初生重整体较大,其中以1月出生的羔羊初生重最大;出生类型越丰富,其羔羊初生重越小,各出生类型间羔羊初生重均呈现出极显著差异(P<0.01);根据单性状动物模型(考虑母体效应)的计算得出,湖羊初生重性状的直接、母体、总体遗传力分别为0.251、0.668、0.211,属于中等遗传力。【结论】在对羊场首年的生产数据分析...  相似文献   
53.
The antinociceptive effect of the ethanolic extract of Melastoma malabathricum (MME) was investigated using acetic acid-induced abdominal writhing test and hot-plate test in mice. It was demonstrated that the extract (30-300 mg/kg, i.p.) strongly and dose-dependently inhibited the acetic acid-induced writhing with an ED(50) of 100 (78-160) mg/kg i.p. It also significantly increased the response latency period to thermal stimuli. Furthermore, the nonselective opioid receptor antagonist, naloxone blocked the antinociceptive effect of the extract in both tests, suggesting that M. malabathricum may act both at peripheral and central levels.  相似文献   
54.
Seaweeds are valuable sources of biologically active compounds that could be used as ingredients for pharmacological applications. Industrial fermentation using microorganisms provides a wide array of fermented foods and functional compounds with excellent health benefits. These fermentation-derived natural compounds have the potential to be applied as nutraceuticals and functional foods. Therefore, this paper presents an overview of the fermentation of sustainable seaweeds in producing valuable components, including anticoagulant, antioxidant, antimicrobial, anti-inflammatory, and anticancer. Fermentation-derived compounds are expected to receive more attention due to their environmentally friendly processing as well as consumer desire for natural foods.  相似文献   
55.
巴什拜羊与野生盘羊后代杂种的适应性分析   总被引:1,自引:0,他引:1  
对野生盘羊与纯巴什拜羊杂种后代的生长发育、总繁殖率、常见病发病率、抗寒能力等适应性性状与纯巴什拜羊进行了比较。结果表明,杂种一代羊的适应性较差,而回交二代羊的适应性(其总繁殖率105%,4.5月龄体重达35.8kg,常见病发病率3.3%)最好,杂交效果明显,是培育瘦肉型巴什拜羊新品系的主要组合。  相似文献   
56.
Canines are definitive hosts of Neospora caninum (Apicomplexa). For horizontal transmission from canines to occur, viable oocysts of N. caninum must occur in the environment of susceptible intermediate hosts. Canids in Australia include wild dogs and Aboriginal community dogs. Wild dogs are those dogs that are not dependent on humans for survival and consist of the dingo, feral domestic dog and their hybrid genotypes. Aboriginal community dogs are dependent on humans, domesticated and owned by a family, but are free-roaming and have free access throughout the community. In this study the extent of N. caninum infection was determined in a total of 374 dogs (75 wild dogs and 299 Aboriginal community dogs) using a combination of microscopic, molecular and serological techniques. Oocysts of N. caninum were observed in the faeces of two juvenile Aboriginal community dogs (2/132; 1.5%). To estimate N. caninum prevalence, a new optimised cut-off of 18.5% inhibition for a commercial competitive ELISA was calculated using a two-graph receiver-operating characteristic (TG-ROC) analysis and IFAT as the gold standard resulting in equal sensitivity and specificity of 67.8%. Of the 263 dog sera tested the true prevalence of N. caninum antibodies was 27.0% (95% confidence limit: 10.3-44.1%). The association between the competitive ELISA results in dogs less than 12 month old and older dogs was significant (P=0.042). To our knowledge this is the first large scale parasitological survey of the Aboriginal community dogs and wild dogs from Australia. The high prevalence of N. caninum infection in Aboriginal community dogs illustrates that horizontal transmission of N. caninum is occurring in Australia. These results demonstrated that N. caninum in dogs is widespread, including the semi-arid to arid regions of north-western New South Wales and the Northern Territory. The populations of free-ranging dogs are likely to be important contributors to the sylvatic life cycle of N. caninum.  相似文献   
57.
‘火州红玉’葡萄是以‘红地球’为母本,‘火焰无核’为父本进行杂交选育而成的新品种。在新疆鄯善地区果实8月中旬完全成熟。果粒近圆形,果皮紫红色,平均单粒质量3.1 g,无核,果肉脆,味酸甜,可溶性固形物含量21%,总酸3.63 g · kg-1,耐贮运,栽培适应性较强。  相似文献   
58.
Pathological lesions of the mammary glands were studied in 3693 randomly selected ewes in Northern Iraq between July 1988 and June 1989. The lesions were encountered in 3.9% (143/3693) of the ewes. Prevalences of mastitis, neoplasms and miscellaneous lesions were 3.5% (131/3693), 0.2% (6/3693) and 0.2% (6/3693), respectively. Five patterns of mastitis were encountered: acute suppurative, subacute suppurative, subacute non-suppurative, chronic suppurative and chronic non-suppurative. Mammary neoplasms encountered in the present study included adenocarcinoma, papilloma of the skin of the teat and haemangiopapilloma of the cistern. The miscellaneous lesions of the mammary gland included subepidermal cysts; hyperplasia, metaplasia and dysplasia of the ductal epithelium; thelitis; the presence of corpora amylacia; and blind teats. The highest prevalence of mastitis was during May and June. Significant differences were not encountered in the prevalence of mastitis in various age groups and breeds. Bacteria that were isolated from mastitic udders included Staphylococcus spp., Corynebacterium pyogenes, Pasteurella hemolytica, Pasteurella multocida, and a mixture of Escherichia coli and Staphylococcus spp. The staphylococci were isolated from almost all types of mastitis, C. pyogenes from chronic supparative mastitis, and the pasteurellae from the acute and subacute mastitis. Fungi were not isolated.  相似文献   
59.
实验旨在比较新疆5种野生葱属植物叶片解剖,分析其适应环境能力,筛选出适宜推广的野生葱属植物。本实验以引种在新疆农业大学试验基地的5种野生葱属植物叶片为实验材料,通过石蜡切片法,在光学显微镜下观察叶片解剖结构。实验结果显示,1号、4号和6号的大维管束数越多,叶片长势越好,适应能力强。2号和3号的大维管束数越少,叶片长势越弱,适应能力差。1号、4号和6号的适应环境的能力比2号、3号强,可在适宜区域进行推广。  相似文献   
60.
Genetic transformation of rice(Oryza sativa L.) by introducing beneficial traits is now a central research instrument in plant physiology and a practical tool for plant improvement. Many approaches are verified for stable introduction of foreign genes into the plant genome. The review examined the different constraints that limit the success of rice genetic transformation via Agrobacterium-mediated approach and suggested possible solutions. Explant identification, gene transfer technique and construct to tailor the integration, transgene expression without collateral to genetic damage and transformant selection are among the technical challenges affecting the rice transformation. Despite the contests, Agrobacteriummediated transformation system has been a better option for producing transgenic rice varieties because of its exact T-DNA processing and simple integration of low copy-number transgene. This information is necessary for improving the transformation system for recalcitrant rice varieties.  相似文献   
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